ABSTRACT (Untargeted Analysis Resource) The primary objective of the Untargeted Analysis Resource of the Michigan Children?s Health Exposure Analysis Resource (M-CHEAR) is to provide external investigators with a resource to design and execute studies which will analyze large number of metabolites from children?s blood, urine, tissues and other matrices to identify potential biomarkers that will reflect phenotypes arising from environmental exposures. The Untargeted Analysis Resource will leverage the infrastructure and expertise of the Michigan Metabolomics and Obesity Center which has proven expertise in working with scientists across disciplines to carry out large scale discovery projects. Multiple platforms will be employed in the Untargeted Analysis Resource including Reverse Phase-Mass Spectrometry (MS), hydrophilic interaction liquid chromatography (HILIC)-MS and Gas Chromatography (GC-MS). Each can be employed by individuals to ascertain the relative concentrations of thousands of metabolites in biological samples. In addition, the Untargeted Analysis Resource offers a High Dimensional Lipidomic platform that can provide accurate and reproducible analysis of ~700 of lipid species from up to 26 classes of lipids with ~1700 additional lipid species reproducibly identified. The processes for the Untargeted data have extensive SOPs which are employed to assure quality data including multiple platform-specific internal standards, pools of experimental samples (where appropriate) and standard within- lab pools. These standards are used to assess instrument performance and within and between batch normalization. The identification of compounds in the untargeted metabolomics profile will be enhanced by the availability of a library of nearly 1000 authentic metabolites whose spectral features have been determined on each of the platforms and a library of ?known unknowns?, features that are identified reproducibly in plasma samples. The Untargeted Analysis Resource will also provide procedures for randomization and blocking of samples for analysis and methodology for data normalization and imputation of missing data, prior to data analysis. The Resource provides a suite of tools for data analysis for ?mining? of the data, statistical analysis, and data visualization. The Untargeted Analysis Resource also will be responsible for data curation, annotation and storage and will work with the Data Coordinating Center and the Data Resource in the design and analysis of data and proper sharing of the data in a HIPAA-approved manner. The Untargeted Analysis Resource will work with the other CHEAR Hubs to share techniques and information to improve the efficiency and accuracy of data derived from the analytical platforms. Finally, working with the other Resources at the M- CHEAR, we will be able to offer the unique expertise in integration of the analysis generated by the Untargeted Analysis Resource with other clinical and molecular phenotypes to derive knowledge of the effects of exposures and diet on the health of children.